At the present, there is an increasing need for high speed non-impact printing in order to provide the "hard copy" output of the latest technology in computer processing.
As paper for computer printing is produced in two formats, either continuous forms or sheets, manufacturers have developed printers to accommodate one or the other type of format.
When a printer operates with continuous paper forms that are attached to each other, the continuity of the printed matter remains in the proper order for post-printer processing such as mailing or binding operations. However, when printers operate with separate sheets of paper, the retention of the single sheets in their proper order with respect to one another is difficult and often impossible. One reason is that today's methods require manual handling of large stacks of paper which can easily spill or fall and get out of sequence.
There exists a number of non-impact sheet-fed printers which have one or two input hoppers which allow the printer to take individual sheets and pass them through the printing mechanism for the placement of the image onto the paper surface. Upon exiting from the printer, the sheets are placed face down into a receiving hopper or a container.
The printed sheets are delivered with the printed surface face down and, therefore, the first sheet printed must be the first sheet processed in any post-printing operation. Since the output hoppers have a limited capacity, it is necessary to continually take out small quantities of printed sheets, e.g., 500, and place them face down, on a table or pre-staging area. Because the sheets are face down, it is difficult for anyone to know exactly which group of printed sheets follow the preceding group.
In addition, there are either many small stacks of sheets or a few large stacks of sheets which can easily fall and get out of their proper sequence. In any event, intensive manual handling of sheets of paper is necessary.
One attempt to solve the above problems is the use of a container which fits into the output hoppers to accumulate the papers as they are printed and place them in containers with an upwardly moveable bottom which is capable of holding approximately 2,000 sheets. The method of collecting the paper into the container is to place the container over a narrow elevator center post and lower the box over the post so that the bottom rests on the post. As the container is filled with sheets, the elevator is lowered. Manual handling is again needed to stack the paper on tables, etc., for future processing.